xas Packet Radio Society TexNet: internet and weather Digital Communications and Packet Radio Bob Morgan, WB5AOH
Dec 23, 2015
Texas Packet Radio Society 1
TexNet: internet and weather
Digital Communications
and Packet Radio
Bob Morgan, WB5AOH
Texas Packet Radio Society 2
Topic List
Weather Service topics Demand for Packet by Austin ARES TexNet network code development Internet trunking for TexNet network Questions and Answers
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TexNet weather servers status
TULWX - operational NWS - being relocated again BROWX - operational STXWX - under construction EMWIN CARDINAL server - development
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EMWIN status
EMWIN now fed at 9600b from satellite EMWIN local feeds locally filtered Satellite failure in May 1998 GOES satellite alternative
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EMWIN WWW URL
http://www.nws.noaa.gov/oso/oso1/oso12/ document/emwin.htm
http://www.amrad.org/skywarn.html
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APRS and TexNet and Weather
development effort to use APRS to aid weather spotting and reporting
development effort to use TexNet to aid in networking of APRS, particularly weather spotting and reporting
growing array of APRS weather stations, including those at TexNet nodes
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WinAPRS and weather mapping
WinAPRS is being oriented towards NWS alerting, mapping, and spotting
WinAPRS street level maps available for almost all counties in the US. These are large files and require much memory
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Packet use in ARES in Austin
One packet message never sent ARESDATA used in casualty exercises Demand for Packet operators and portables packet node under construction for ARES
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TexNet net code development
Vers 1.74 is current, 1.72 useable Vers 1.75 under development, still buggy NCP or NCPPC platform TNC2 platform TNC2 dualport platform
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TexNet vers 1.75 goals
TNC3 platform, 4 ports APRS tracker, digi, etc. WIDE-N repeat DXC reconnect fix Telemetry Internet trunking or KISS interface Won’t drive PMS disk (memory
bankswitching being investigated here)
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TexNet over the Horizon
Port Cardinal, Weather servers, etc to LINUX systems
Port TexNet layer 3 Net Code to Linux Add many applications to TexNet under
LINUX when layer 3 is moved there Allow for using newer PC hardware Eventual interface with Amateur S.S. nets
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Internet Trunking for TexNet
Using the internet to supply new trunk paths to connect various sections of TexNet together
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Why the internet, why not radio?
Wireline availability reduced as times change
Internet is available, technology is off the shelf, we just apply it to our situation
Economic realities Reliability issues of the three methods
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TexNet network layout - radio
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TexNet with Wirelines
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TexNet with internet additions
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Network Economic Realities
New radio node cost $500-$2000 or more We might need 20 or more nodes, more
than that for any redundancy Maintenance problems increase
dramatically Reliability and throughput reduced Crosses point of diminishing returns
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Reliability Issues
Radio or path can be unreliable also Many nodes in series are unreliable Switched networks unreliable Increase reliability by redundancy Increase reliability by use of different types
of trunking in parallel Re-routing issues
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Relative reliability
Fiber optic leased circuits probably best Good radio paths decent, but not best Internet is pretty decent, lots of possible
failure sites and modes under stress Public switched circuits and cellular
basically unreliable, and this is what makes demand for Amateurs in an emergency due to switching overload by demand.
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Wireline trunk paradigm
channel banks
fiber xcvr
V.29 modem
NCP
Radios
Antennas
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Wireline trunk requirements
Find a provider to donate service and sites Find two or more sites with roof access These sites have to be places we need Sites have to be good RF locations No fees or insurance demands Useable service access for maintenance
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Internet Node layout
NCP
LINUX
ISP SERVER
INTERNET
(AX25IPD)
kiss
ethernet
T-1
UPS
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Internet Service Providers
Probably will be different in every locality We want donated full time service Service can be limited to one type protocol We want to tie to ISP at ethernet speeds We want the ISP to have T1 speed to net We need some kind of RF access at site UPS almost a necessity for our PC, etc.
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AX25IPD routing topology
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AX25IP Encapsulation- raw IP
LAN
Hdr.
IP
Hdr. DATALAN
Trlr.
AX.25ADDRESS
Control DATA FCS
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AX25IP Encapsulation - UDP/IP
LAN
Hdr.
IP
Hdr. DATALAN
Trlr.
AX.25ADDRESS
Control DATA FCS
UDP
Hdr.
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Present Firecode HardwareData
Clock
Modem RX Long shift register
Programmed recognition data
ANDResetNCP
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Internet Firecode Hardware Conceptual design
NCP Reset
PC Reset
PC KbdSocket
clk
dataShift register cntl-alt-del
Linux reboot
1
2
3
Modem RX clk
data
long shift register
stored patterns
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Internet Security Issues
Keep all internet hackers out of systems Keep ham hackers out of TexNet internals Keep non-ham people off the air Allow for limited remote control by sysop Measure and report stats and breakins Allow for re-routing if network stressed
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Internet Security Methods
Remove compilers, editors, ftp, etc If we are behind a firewall, use it also Use and change passwords on remote route Automated file change surveillance Automated suspicious port activity surv. Deception responses from unused ports
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LINUX .....FOR IQ’S HIGHER THAN 95.....